A number of industries, including the forest by-products, landscaping, and playground industries have long been in need of efficient methods and apparatus for transporting, dispensing and distributing non-free-flowing or loose particulate materials. An exemplary but non-exclusive list of commonly distributed non-free-flowing or loose particulate materials includes loose bark, wood chips, sawdust, compost, etc. Applications for such materials include residential and commercial landscaping and playground installations.
As society recognizes the increased need to improve the safety of playgrounds, it is increasingly important to cover areas surrounding playground equipment with a cushioning material. Such materials cushion a child's fall thus reducing the occurrence of injuries. Some of the commonly used playground cushioning materials include loose bark, wood chips, sawdust, rubber particles, etc.
In the past, it has been difficult to safely and efficiently transport and apply loose particulate materials to the application site. Loose particulate materials are generally trucked on site in a dump truck, unloaded and then distributed manually using wheelbarrows, shovels, rakes, etc. To increase the efficiency of the distribution process, the present inventor invented a container truck to transport and distribute loose particulate materials. The container truck includes an open top through which the truck can be filled using a front-end loader or other loading equipment. The container truck includes a moving floor or conveyor. The moving floor moves loose particulate material within the container into a material feeder at the rear of the container. The material feeder provides a regulated flow of loose particulate material into an air stream from a powerful blower. Loose particulate material exiting the feeder mixes with the air stream from the blower and is blown out of the container through an attached hose. An operator applies loose particulate material by pointing the free end of the hose at the location, where the loose particulate material is desired.
Although the inventor's previous invention dramatically increases the efficiency of the dispensing and distribution process, it has room for further improvements. The moving floor sometimes moves loose particulate material over the feeder so that it "bridges," e.g., blocks the passageway to the feeder, thus preventing material from entering the feeder. An operator must then enter the container truck to break up the loose particulate material so that it falls into the feeder.
In order to prevent bridging or blocking of the feeder, a second operator is located within the container to redistribute or break up the loose particulate material. However, placing an operator within the container is undesirous because the operator is located adjacent to dangerous equipment including the moving floor and feeder. In addition to increasing the possibility of injury, the use of two operators adds to overall distribution costs.
Another concern identified during the operation of the container truck was the production of a great deal of airborne particles. Blowing dry loose particulate materials such as wood chips or sawdust creates a large quantity of airborne particles or dust. The airborne particles create an unpleasant working environment for the operator and people within the vicinity of the application process. In addition, the Environmental Protection Agency (EPA) is investigating whether airborne particles present health concerns for operators or bystanders. The EPA has urged the industry to research methods to distribute dry loose particulate materials without creating large quantities of airborne particles.
Thus, a need exists in the industry for methods and apparatus to distribute loose particulate materials that reduce or eliminate some of the problems of prior distribution systems. The present invention is directed towards fulfilling some of these needs.